$\dfrac{5}{3} - \dfrac{4}{12} = {?}$
Answer: $ = {\dfrac{5 \times 4}{3 \times 4}} - {\dfrac{4 \times 1}{12 \times 1}} $ $ = {\dfrac{20}{12}} - {\dfrac{4}{12}} $ $ = \dfrac{{20} - {4}}{12} $ $ = \dfrac{16}{12}$